Association between body mass index and body fat measured by dual-energy X-ray absorptiometry (DXA) in China: a systematic review and meta-analysis

Objective:We examined the association between body mass index(BMI)and body fat percentage(BF％)measured by dual-energy X-ray absorptiometry(DXA)among adults and children in China.Methods:We searched four databases-PubMed,China National Knowledge Infrastructure,Wanfang,and Vip for studies published in the past 22 years.Meta-analysis was conducted using random-or fixed-effect models.Results:In total of 21 studies met inclusion criteria and were included in review,and 17 ot them in meta-analysis.They were conducted across China.Their sample size ranged from 62 to 5 726,and participants'age ranged from 6-80 years.Meta-analysis revealed strong associations between BMI and BF％measured by DXA in adults(pooled r=0.71,95％CI:0.66 to 0.74)and children(pooled r=0.60,95％CI:0.52 to 0.68).The association was stronger in Northern China than in East China in children(β=-0.40,95％CI:-0.65 to-0.14)and in Central China in adults(β=-0.25;95％CI:-0.51 to-0.01).Urban children's BMI was strongly associated with BF％than rural(β=0.19;95％CI:0.04 to 0.35),whereas it was stronger in adults living in rural than in urban(β=-0.35;95％CI:-0.66 to-0.05).Conclusions:BMI was strongly associated with BF％measured by DXA,and the association in children and adults in China varied by residence and region.